Add support for generator / processor configuration

[DerManoMann]

Allows to configure processors (and the Generator itself).

To kick things of the only option is to toggle the OperationId processor hash flag.

Default config:

[
    'operationId' => [
        'hash' => false
    ]
]

Top level key must match the processor class name (with a lower case'd first char).
Settings are applied via setXXX() methods, so unless there is a matching method for the config option nothing will happen.

A minor BC break is that the config is applied each time Generator::getProcessors() is called. This allows to also configure custom processors the same way.

For obvious reasons, callable processors are skipped :)

The actual BC break is that swappng the OperationId processor for an instance with different configuration wil no longer have any effect.
On the plus side it is a lot simpler to just call setConfig() than swapping a processor.